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T. Tomovic, M. Dietrich, D.M. Crenshaw (Georgia State University)
Among the defining properties of active galactic nuclei (AGN) is their variable energy output with a great variety of variability in strength and duration over the entire electromagnetic spectrum. The observation of continuum variations, emphasizing timescales, amplitudes, and spectral shape chances, over a wide spectral range allows to study the nature of the responsible emission processes, for example thermal emission of an accretion disk or the role of reprocessed emission. We will present results of an optical/infrared monitoring campaign on two southern Seyfert 1 galaxies. We observed IRAS 09149-6206 and ESO 141-G55 from Februray until July 2003 with a sampling of 5 days using the 1.3m telescope at Cerro Tololo InterAmerican Observatory. The observations were obtained as part of the SMARTS (Small and Moderate Aperture Research Telescope System) Consortium observing time. The optical and near-infrared fluxes in B, R, J, and K-band of each AGN are calibrated with respect to several comparison stars of comparable brightness in the field of the corresponding AGN. The flux contribution of each host galaxy was carefully estimated to isolate the AGN broad band flux. We will show lightcurves of the flux variations of IRAS 09149-6206 and ESO 141-G55 in B, R, J, and K bands, the strength and timescale of the variations, as well as changes in the overall spectral continuum shape will be discussed. In addition, we will scrutinize the vicinity of both Seyfert 1 galaxies for faint objects with unusually red colors, e.g. searching for red objects which start to become visible in R-band frames and particularly in the near infrared J and K-band.
The author(s) of this abstract have provided an email address for comments about the abstract: tomovic@chara.gsu.edu
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Bulletin of the American Astronomical Society, 35#5
© 2003. The American Astronomical Soceity.